Research On Cooperation Problem Of Online Steady-state Power Flow Calculation With Real-time Measurements

Steady-state power flow calculation can calulate the operation status of power grid according to given power grid operation condition and network structure, wich is a basic electrical calculation in power system analysis. This paper summarized the premises of steady-state power flow calculation:energy conservation, steady-state measurements, single frequency, power flow calculation results keep the pace with measured data.Both theoretical analysis and simulation results demonstrated that, only steady-state measurments can meet the requirements of steady state flow calculation premises. However, due to reality operation reasons, such as power load fluctutations, renewable energy grid-intergrated generating and switching operations, the power grid oftenly-operate in dynamic state rather than steady state, not to mention the constant state. Therefor, it is not appropriate to applicate the telemetry data based on SCADA in state estimation, the real-time measurements should be processed.To slove this data cooperation problem of real-time measurements with power flow calculation, two data processing methods are put forward. One for quickly remove transient data method, which can make self-adaptive adjustment according to different data precision requirements in practical applications, eliminate the transient meaurements quickyly and dfficiently in accordance with the requirements of data precision. However, this method is only applicable to engineering analysis, not in the analytic expressions. Secondly, multicycle effective value method can satisy the prerequisities of steady-state power flow calculation in analytic expression, whose data processing results can reflects the dymanic operation status of power grid comprehensively, making up for the deficiency of the former method.The simuliations are performed in MATLAB/SIMULINK software platform, which take the double-generators-infinite-system as an example, imitate power flow in reality by using power load perurbation model. The simulation results verify the validity and correctness of the above theoretical derivation.